Textile machine units



April 19, 1960 .1. ROCKOFF 2,932,859

TEXTILE MACHINE uurrs Filed Nov. 10, 1954 INVENTOR. JOSEPH ROCKOFF United States Patent TEXTILE MACHINE UNITS Joseph Rockoff, Dayton, Ohio, assignor to The Dayton Rubber Company, a corporation of Ohio Application November 10, 1954, Serial No. 468,011 9 Claims. (Cl. 19-143) The present invention relates to textile machinery units and particularly to rolls or roll covers known as cots for use in the carding, drawing and spinning of textile yarns. This application is a continuation in part of copending application No. 781,581, filed October 23, 1947, now abandoned, which is in turn a continuation in-part of application Serial No. 452,132, filed July 24, 1942, now U.S. Patent No. 2,437,362, granted March9, 1948.

While this invention will be described in connection with the making of a spinning roll cot, it will be understood by those skilled in the artthat the same is also adapted for forming other rolls commonly used in textile working machinery, such as temple rolls, loom take up roll coverings, slasher rolls, and the like. These same rolls, of course, may find additional utility in other fields such as printing, material handling and the like.

The improved spinning roller or cot which is the subject matter of the present invention possesses good fiber drafting characteristics, exhibits low static charge buildup, is resistant to attack by oil and abrasive substances, and has good aging and wear resisting properties. In addition, it is characterized by a surface which exhibits no tendency to eye-brow" and. which retains its original finish or condition in spiterof normal wear through abrasion.

It has been conventionalpractice to make spinning and fiber drafting cots of leather, cork and similar substances. Cots made of leather and cork are resistant to oil but have very poor abrasion resistance and a tendency to develop grooves or a scored or uneven .surface during use thus necessitating their removal for repair or replacement. Calf skin. possesses the desired surface characteristics for working fibers but tends to wear out rapidly due to its low resistance to abrasion.

Many attempts to employ synthetic materials, in particular, synthetic resins and rubbers, in the manufacture of spinning rollers and cots, have been made, but/they have proved unsuccessful. f-There is some belief that the failure of these" materials was due to electrostatic charges accumulating 'on the units during operation. Thus neoprene, butadiene-styrene copolymers and other similar resinous materials including 'methyl 'rubber, polysulphide rubbers,,polyvinyl chloride, and alkyd resins werefound not to be satisfactory, because textile units made from these materials exhibit excessive eye-brewing and have a tendency to lap up the fiber being worked.

More recently it has been found that acrylic nitrile butadiene copolymers, when compounded with the con ventional auxiliary rubber ingredients and vulcanized,

produce a cot which is greatly superior to a cot made of any other of the above listed materials. While cots composed of acrylic nitrilebutadiene copolymer rubbers have goodfiber drafting properties and exhibit substantially no tendency to collect static charge or fibers on the surface, nevertheless, there is still room for improvement.

2,932,859 Patented Apr. 19, 1960 In accordance with the present invention, a method has been devised by means of which all the materials discussed above, namely, the synthetic rubbers such as the butadiene-styrene copolymers, neoprene, methyl rubber, polysulphide rubbers, as well as polyvinyl chloride and alkyd resins, and particularly the buttadiene-acrylic nitrile copolymers may be made operative as improved cots and other rolls used in textile working machines. In fact, all these materials, when treated according to this invention, yield textile rolls that are far superior to any other rolls used heretofore, the rolls made of acrylic nitrile butadiene copolymer rubbers having proved the very best.

The above mentioned treatment according to this invention comprises the admixing with the above enumerated rubbers or resins in their uncured state of a minor proportion of particles of hard siliceous materials. Such particles include those of the various silicas and silicates such as quartz, sand, flint, chalcedony, opal, agate, rock or glass. It has been found that these particles of fused or crystalline silica or silicates have certain physical properties with regard to their hardness and surface characteristics which account for their advantageous use in cots or roller compositions, especially when treated as hereinafter more fully described. While hard particles may be defined generally as those having a hardness of 5 or more on the Mohs scale (see Chemical Engineers Handbook by John H. Perry, 3rd edition, 1950, page 1114), applicant has found that silica or silicate particles within a hardness range of from approximately 7 to approximately 8 on the Mohs scale provide particularly satisfactory textile cots or roll covers. As. set forth in copending application, Serial No. 781,581 filed October 23, 1947, it has been found that, of the above described class of particles, sand gives especially satisfactory results when incorporated in cot compounds and treated as hereinafter set forth. Similarly, particles of fused silicon dioxide in the form of glass and particularly particles in the form of spheres or beads of glass have been found to improve resistance to eyebrowing and lapping up. When these and similar sicila or silicate particles and especially such of those as have a hardness from approximately 7 to approximately 8 on the Mohs scale are incorporated in a matrix composition of any of the above enumerated rubber or resinous substances, not only is a special support provided the working surface of a roll or cot formed thereof but also, when the working surfaces of the cots are ground in the customary manner, the voids or cavities left by the evacuation of these particles from the surface have proved capable of producing unexpectedly advantageous working surface characteristics. Applicant has found that improved results may be achieved where the particles of sand or glass range in size from about 0.003 to 0.03 inch from about 20 mesh to 200 mesh U.S. standard sieve classification in diameter. While a minor proportion or less than 100 parts by weight of the particles to 100 parts by weight of the rubber-like composition has been found to give satisfactory results, especially suitable textile cots have been made from compositions according to this invention wherein the weight ratio of particles to the rubber-like copolymer has been within the preferred range of from 50 to parts of the sand or glass beads to parts of the copolymer. In general, any proportion which will not seriously impair the rubber-like or elastomeric characteristics of the base material may be used, the minimum being that amount which will provide improved surface characteristics after grinding which may be as small as one part per one hundred parts by weight of the rubber. As indicated above, a preferred maximum is one hundred parts of the particles per one hundred parts by weight of the elastomeric material.

There are several theories which might explain the improved fiber drafting properties imparted to cots manufactured according to the present invention. One such theory involves theconcept of an increase of surface area resulting from the presence of the voids or cavities left by the evacuation from the matrix composition of the previously described particles which results in an increased ease of dissemination of a static charge. The phenomenon of *point discharge may also occur on the myriad little points at the edges of the cavities formed by the evacuation of thesilica particles from the cot surface. Finally, these cavities appear to act as suction cups and thereby increase the gripping action of the unit thus compensating for any eyebrowing tendency which would result from the fibers parting'too readily from the roll surface. It is also probable that more than one of these phenomena takes place and that certain of these reactions coact and thereby bring about the most desirable result of a static free non-eyebrowing textile unit capable of operating for long periods of time without lapping up or becoming slick, worn or otherwise unusable.

The following is a typical example of a spinning cot composition:

EXAMPLE (a) Rubber stock Parts by weight Butadiene-ac-rylic nitrile copolymer 80-125 b) Cot composition 100 parts by weight of the rubber stock obtained according to (a) were mixed with from 30 to 70 parts by weight of fine sand. Mixing was carried out in the usual manner using suitable rubber mixing and compounding equipment. Equally satisfactory results were obtained no matter whether the ingredients were added successively orsimultaneously. After the materials were thoroughly mixed, they were molded and vulcanized to form a cot of the desired shape.

The rubber or resin may be used in different amounts, preferably on the order of from 30 to 55 percent by Weight of the stock composition. The final cot compositionis cured or vulcanized as is customary. i

The hardness of the cots may be preferably within the range of 50 t 95 as measured on the Shore type A durometer. The hardness or toughness of the finished article, and its resiliency may be modified by suitable additions of carbon black, zinc oxide, clays and other materials as is well known to those skilled in the compounding of rubber.

In lieu of the sand particles set forth in the example (b) above, small spheres or beads of glass, which is a fused silica usually formed from silicon and an alkali such as sodium or potassium, may be included with a rubber-like matrix composition. A specific composition of this type which has been found to give improved noneyebrowing and lap resistant properties to textile drafting rollers and roll covers is as follows:

Parts by weight Butadiene-acrylic nitrile copolymer 100 Plasticizer' (e.g., tricresyl phosphate) 12.5

Stearic acid .625

Zinc oxide; 5.0

Sulfur 6.5

Antioxidant (e.g., di-beta-napthyl-para-phenylenecliamine) 1 4 Accelerator (benzothiazyl disulphide) 1.25 Coumarone indene resin 7.5 Soft clay filler 30 Solid glass beads 60 These glass beads, like the sand particles in the previously given example, are preferably thoroughly mixed in the rubber-like matrix composition during the regular mixing involved in the compounding thereof, such mixing taking place on a mill or in a baubury as is the common custom in compoundingrubber-like material.

Once the rubber-like composition containing the sand or glass bead particles is thoroughly mixed, it is formed into the rolls or roll covers by well known methods such as by being forced through extrusion dies, and the articles thus formed are subjected to vulcanizing conditions according to common well known practice, usually by rag wrapping and placing the wrapped article in an open steam vulcanizer. During this vulcanization the rubber-like matrix composition will assume its elastomeric properties and the silica or silicate particles will become permanently set therein. The plastic flow of the matrix composition attending this vulcanization is such that the particles near the surface of the roll cover will be covered with a thin film of the rubber-like material. Accordingly, to uncover the surface particles and to remove the impression of the rag wrapper, the'roll covers or cots are removed from'the vulcanizer and subjected to a grinding and bufiing action until they are brought to proper working dimensions and surface characteristics. i

It is .during this grinding operation that the surface particles in the form of hard silica or silicates such as sand or glass beads within the hardness range of approximately 7 to approximately 8 on the Mohs scale are removed from the working surface to provide the desired voids and cavities as above described. It has been found that the removal of these various particles from the matrix composition to provide the desired voids results primarily from the coaction of the grinding or bufiing wheel against the elastomeric rubbery material which squeezes those particles near the surface of the matrix composition out of the roll. Softer particles on the other hand will become broken during the'grinding or will simply be ground down to a surface flushwith the working surface of the cot. In substantially all cases utilizing particles according to this invention however, those near the surface of the cot are squeezed from the surface thereof such that only the voids or cavities left by the evacuation of these particles remain upon the working surface.

The working surface of the cot, once abraded and blown so as to remove the particles which have been substantially squeezed from the roll surface will be substantially non-self-regenerating; that is, the cot or similar textile working unit will not wear away to the extent that the cavities formed by the removal of the particles will be worn away and new particles will appear on the surface. Certain other factors, such as the swelling effect of the action of textile oilsupon the rubher-like matrix material, the deteriorating effect of sunlight, the accumulation of lint from the .yarnsbeing processed, etc. will cause the cots or roll covers employed in the textile art to lose their desirable properties. In this case, the cot may be removed from the machine on which it is operating and subjected to a new grinding or abrading action as is the custom in the textile art. This abrading action in the case of the cots of the present in vention will wearaway that surface of the rubber which contains the voids left by the previous evacuation of the particles and will at the same time present a new surface from which the particles will be newly removed as in the case of the grinding of a new rolleras explained above.

The invention, thus generally described, and the objects and advantages to be gained from the practice thereof may be more fully understood by reference to the following detailed description in connection with the appended drawings.

In the drawings:

Figure 1 is a perspective of a top spinning roller or cot according to the present invention.

Figure 2 is a cross section on line 2-2 of Figure 1 showing the roller thereof in cross section.

Figure 3 is a perspective of another top spinning roll or cot according to the present invention.

Figure 4 is a view on the line 44 of Figure 3 showing the roll cover and arbor thereof in cross section.

Referring now to Figures 1 and 2 and one preferred embodiment of the present invention, the spinning roll or cot assembly generally referred to by the No. is shown to consist of a metal arbor designated generally as 11 which itself consists of a shaft or axle 12 and raised roller bosses 13. About these raised bosses 13 are positioned the roll covers or cots 14 forming the subject matter of the present invention. The cot 14 comprises a matrix 15 of elastomeric composition according to one of the previously set forth examples incorporated with which are a plurality of glass beads 16. The cavities 17 left upon the surface of the cot by the evacuation of these spherical beads 16 therefrom are themselves spherical. Reference to Figure 2 and the cavity 18 formed by the removal of a glass bead substantially wholly embedded in the rubber matrix immediately prior to its removal by the action of the grinding wheel thereon will disclose the peculiar nature of the cavities formed according to this invention. The opening 19 of this cavity upon the working surface 20 of the cot is of smaller dimension than the largest dimension of the cavity beneath such surface. As a result of this, a very sharp line is provided around the surface opening of the cavity this line being designated at 21 and providing a resilient lip of rubber about the top of the cavity which will play an important part in the dissemination of the accumulated static charge and the ability of the working surface to hold textile fibers by a suction or mechanical gripping action.

The cot shown in Figures 3 and 4 is similar to that above described consisting of a Wood or metal arbor 22 about which the annular roll covers or cots 23 are positioned. The cots in these figures, however, represent a rubber-like matrix composition 24 with which have been incorporated a controlled quantity of sand particles 25. In accordance with the above described procedures involving the use of glass beads these sand particles 25 are removed from the working surface of the cot to provide the cavities 26 by the grinding operation as set forth in connection with the glass beads of Figures 1 and 2. While the cavities provided by the sand do not have the uniformity and regularity of the glass beads, it has been found that the peculiar nature of the sand enables it to be squeezed or popped out of the working surface of the cot by the grinding action to impart the cavities 26 which are not unlike those left by the glass beads.

While the present invention has been described in connection with specific embodiments it is to be understood that this description is for purposes of illustration only and is in no way intended to limit the scope of the invention as it is defined by the subjoined claims.

I claim:

1. A non-eyebrowing cot for processing textile fibers comprising a cylindrical member composed of a vulcanized elastomeric composition having a minor proportion by weight of finely divided granular silica particles dispersed therein, said member having a smoothly ground outer surface substantially free from silica particles and having a plurality of cavities corresponding in size and shape to said silica particles vacated from said surface.

2. A non-eyebrowing cot for processing textile fibers comprising a cylindrical member composed of a vulcanized elastomeric composition having a minor pro portion by weight of finely divided granular, hard siliceous particles dispersed therein, said member having a smoothly ground outer surface substantially free from said particles and having a plurality of cavities corresponding in size and shape to said particles vacated from said surface.

3. A non-eyebrowing cot for processing textile fibers comprising the combination of a body of elastomeric material, a minor proportion by weight of granular particles of the class consisting of fused and crystalline silica particles dispersed therein, and means for increasing the gripping action of said cot and for preventing lapping up of said fibers, said means consisting of a plurality of cavities on the surface of said cots, said cavities being formed by the said particles vacating said surface.

4. A non-eyebrowing cot for processing textile fibers comprising the combination of an elastomeric body, a minor proportion by weight of granular particles of the class consisting of sand and glass dispersed therein, and means for increasing the gripping action of said cot and for preventing lapping up of said fibers, said means consisting of a plurality of cavities on the surface of said cot, said cavities being formed by said particles vacating said surface.

5. A non-eyebrowing cot for processing textile fibers comprising the combination of a vulcanized elastomeric body, a minor proportion by weight of granular silica particles ranging in hardness from approximately 7 to approximately 8 on the Mohs scale dispersed therein, and means for increasing the gripping action of said cot and for preventing lapping up of said fibers, said means consisting of a plurality of cavities on the surface of said cot, said cavities being formed by said silica par ticles vacating said surface.

6. A non-eyebrowing cot for processing textile fibers comprising the combination of a vulcanized body, a minor proportion by weight of granulated sand particles dispersed therein and means for increasing the gripping action of said cot and for preventing the lapping up of said fibers, said means consisting of a plurality of cavities on the surface of said cot, said cavities being formed by the evacuation of said particles from said surface.

7. -A non-eyebrowing cot for processing textile fibers into yarn comprising the combination of a vulcanized body having a Shore type A durometer' hardness in the range of about 50 to consisting substantially of parts by weight of a rubber composition based on acrylic nitrile butadiene copolymer, 30 to 70 parts by weight of granulated sand homogeneously dispersed therein, and means for increasing the gripping action of said cot with the textile fibers of the yarn, for disseminating static electricity formed during operation and for preventing lapping up of the textile fibers on said cot when it is used in substantially dry condition, said means consisting of a plurality of projections alternating with cavities on the surface of said cot, said cavities being formed by the granules vacating the surface of said cot.

8. A non-eyebrowing cot for processing textile fibers into yarn comprising the combination of a vulcanized body having a Shore type A durometer hardness in the range of about 50 to 95 consisting of 100 parts of a rubber stock composition admixed from 80 to parts by weight of butadiene acrylic nitrile copolymer, 10 to to 25 parts by weight of dibenzyl ether, 6 to 12 parts by weight of coumarone resin, 4 to 8 parts by weight of zinc oxide, 40 to 70 parts by weight of whiting, 1 to 2 parts by weight of sulfur, and 0.9 to 1.5 parts by weight of benzothiazyl disulphide; 30 to 70 parts by weight of granulated sand homogeneously dispersed therein; and means for increasing the gripping action of said cot with the textile fibers of the yarn, for disseminating static electricity formed during operation and for preventing lapping up of the textile fibers on said cot when it is used in substantially dry condition, said means consist ing of a plurality of projections alternating with cavities on the surface of said cot, said cavities being formed by the granules vacating the surface of said cot.

9. A non-eyebrowing cot forprocessing textile fibers comprising a cylindrical member composed of a vulcanized elastomeric composition having a minor proportion by'weight of finely divided granular, hard silicate particles dispersed therein, said member having a smoothly ground outer surface substantially free from silicate particles and having a plurality ofecavities corresponding in size and shape to said silicate particles vacated from said surface.

References Cited in the file of this patent UNITED STATES PATENTS Woodwvard June 23, 1931 Meyer Dec. 9, 1958 

1. A NON-EYEBROWING COT FOR PROCESSING TEXTILE FIBERS COMPRISING A CYLINDRICAL MEMBER COMPOSED OF A VULCANIZED ELASTOMERIC COMPOSITION HAVING A MINOR PROPORTION BY WEIGHT OF FINELY DIVIDED GRANULAR SILICA PARTICLES DISPERSED THEREIN, SAID MEMBER HAVING SMOOTHLY GROUND OUTER SURFACE SUBSTANTIALLY FREE FROM SILICA PARTICLES AND HAVING A PLURALITY OF CAVITIES CORRESPONDING IN SIZE AND SHAPE TO SAID SILICA PARTICLES VACATED FROM SAID SURFACE. 